Device for securing teeth to tooth adapters of an earth-moving machine through pins

ABSTRACT

A device for securing teeth to a tooth adapter of an earth-moving machine includes a pin removably inserted through at least one first aperture on a tooth and one second aperture on a tooth adapter of a machine. The pin includes at least one expanding element adapted to reversibly switch from a retracted position to an expanded position by moving in a plane substantially perpendicular to the longitudinal axis (x-x) of the pin. The device further includes at least one retaining element associated with at least one of the first and second apertures, and provided with at least one seat for at least partially receiving the expanding element when the expanding element is in the expanded position.

TECHNICAL FIELD

The present invention relates to a device for securing implements to heavy machines by means of pins; in particular, said implements may be teeth for earth-moving machines.

BACKGROUND ART

In the field of heavy machines, devices are known which are used for securing implements to such machines by means of pins. Such devices can be used in combination with different type of machines, including earth-moving machines.

With particular reference to the field of earth-moving machines, excavators, for example, are equipped with a bucket or a blade connected to the end of a movable arm for breaking up and moving earth, the characteristics of which may vary extensively.

The bucket of such machines is generally fitted with one or more teeth, or tips, which can be connected thereto in a removable manner, so that such teeth can be replaced when worn or should they break during use, without requiring the replacement of the whole bucket, which would be a very expensive and difficult task.

In particular, the teeth are secured in different ways to protuberances, also known as tooth adapters, arranged along the lower edge of the bucket. An old fastening method requires the use of a pin or key to be forcedly driven with a hammer into a series of holes between the tooth adapter of the bucket and the tooth; once inserted, the pin is received into a deformable element, e.g. a rubber element or ring, which can generate friction that holds the various pieces in position while using the machine.

This method is, of course, not very safe and practical, in particular when small excavators must be used and the room between the tooth adapters of the bucket is not enough to allow the use of a hammer. In addition, when big pins are used much force needs to be exerted with the hammer in order to insert the pin and create the required friction with the ring.

Another problem is the low level of safety for operators using hammers or clubs for inserting the pin.

A further drawback is that such devices work mainly by friction, and the pin has much clearance within the spaces in which it is inserted; therefore, there is more likelihood that the pin might come off, particularly when the bucket is working into hard ground or in the presence of water: in such cases, vibrations and water will remove the thin layer of earth deposited in the interstices between the tooth, the bucket and the fastening device, which is useful for increasing friction and holding the pieces in mutual contact.

When the machine is in use, one or more pins coming off will cause a number of problems, including: higher costs; danger due to fall of tips from the bucket raised above ground; wear of the “uncovered” tooth adapter, and hence of the bucket itself.

For these reasons, in recent years less “invasive” fastening techniques have been developed, which are however not very practical, especially because they are prevalently intended for use in building yard environments, where water and debris are often present.

For example, document ES1068766U illustrates a device comprising a partially threaded through pin, intended for cooperating with a threaded washer having a locking means, e.g. a groove, into which an operator inserts a screw or pin for holding it in position, thereby preventing the parts from coming out of their seat.

An additional drawback is that the (big) through pin and the (small) locking screw must presumably be screwed by using two different wrenches, resulting in a more complex replacement operation. Moreover, when working in an outdoor environment some of these parts may easily get lost, in particular the locking screw.

SUMMARY OF THE INVENTION

It is one object of the present invention to provide a device for securing teeth to a tooth adapted of an earth-moving machine by means of pins, which can be produced in a simple and economical manner.

It is a further object of the present invention to provide a device having a number of functional features, including ease of installation and removal, operator safety, and reliability, mainly due to a reduced risk of losing teeth from the tooth adapters.

In particular, according to one or more embodiments of the present invention, a pin is used which can be manually inserted into and extracted from suitable holes without requiring the use of hammers, clubs or the like; this technology is also referred to as “hammerless”.

According to the present invention, this and other objects are achieved through a device made in accordance with the appended claim 1.

It is to be understood that the appended claims are an integral part of the technical teachings provided in the following detailed description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention will become apparent from the following detailed description, which is supplied by way of non-limiting example with reference to the annexed drawings, wherein:

FIG. 1 is a view of an implement connected to a machine by means of the present invention;

FIG. 2 is an exploded view of one example of a device in accordance with the present invention;

FIG. 3 is a sectional view of the device shown in FIG. 2, in a retracted condition;

FIG. 4 is a sectional view of the device shown in FIG. 2, in an extracted condition;

FIG. 5 is a sectional view along line V-V of the device shown in FIG. 4;

FIG. 6 is a sectional view of a second embodiment of the device;

FIG. 7 is a sectional view along line VII-VII of the device shown in FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the above-listed drawings, a device connects an implement 3 to an implement carrier 4. In particular, implement 3 is a tooth 3, and implement carrier 4 is a tooth adapter 4 of a bucket 5 belonging to an earth-moving machine, e.g. an excavator useful for excavating/moving earth.

As will be apparent to a man skilled in the art, implement carriers 4, in this case tooth adapters 4 of bucket 5, are shaped in such a way as to at least partially enter a cavity formed in implements 3, which are intended for being mounted on the machine and replaced as necessary. It is therefore necessary to use a device capable of firmly keeping implement 3 in contact with implement carrier 4 while the machine is in use.

“Hammerless” device 1 comprises a pin 10 to be removably inserted through at least one first aperture 12 on an implement 3 and one second aperture 14 on an implement carrier 4 of a machine.

Device 1 comprises at least one expanding element 20 adapted to reversibly switch between a retracted position, in which said expanding element 20 is at a minimum distance from the longitudinal axis x-x of said pin 10, to an extracted position, in which said expanding element 20 is at a maximum distance from the longitudinal axis x-x of said pin 10.

In accordance with an advantageous embodiment illustrated in FIGS. 1 to 5, expanding element 20 is adapted to reversibly switch from said retracted position to said extracted position by moving in a plane substantially perpendicular to the longitudinal axis x-x of said pin 10. In other words, expanding element 20 is adapted to reversibly switch from the retracted position to the extracted position by moving transversally relative to the longitudinal axis x-x of pin 10.

Device 1 further comprises at least one retaining element 22 associated with at least one of said first and second apertures 12, 14, and provided with at least one seat 24 for at least partially receiving said at least one expanding element 20 when said at least one expanding element 20 is in said extracted position.

Retaining element 22 is associated with at least one of the first and second apertures 12, 14 through methods which are per se known; for example, it is possible that a cavity, also known as “counterbore”, is formed on at least one of said first and second apertures 12, 14, into which retaining element 22 can be at least partially inserted.

FIG. 1 shows one advantageous embodiment of the present invention, wherein tooth 3 has a cavity into which tooth adapter 4 is inserted, and two first apertures 12 are present on the faces that delimit the cavity; pin 10 is then inserted through the first apertures 12 on tooth 3 and through the second aperture 14 on tooth adapter 4 of bucket 5.

That part of tooth adapter 4 which must be inserted into the cavity of tooth 3 is also known as “catch”; however, reference will only be made below to tooth adapter without departing from the protection scope of the present invention.

FIG. 2 shows one advantageous embodiment of the present invention, wherein pin 10 has a substantially cylindrical outer surface; other shapes are however also conceivable, e.g. prismatic with a square, rectangular, triangular, polygonal, etc. cross-section.

Expanding element 20 comprises a pair of balls on diametrically opposed sides relative to axis x-x of pin 10, which are adapted to move along a radial path while reversibly switching between the extracted and retracted positions.

Further variants are also conceivable, wherein the pin contains a different number of expanding elements 20 (or even just one).

In addition, expanding element 20 may, still in accordance with the present invention, have other non-limiting shapes, including: bar, parallelepiped, cylinder, ellipse, etc.

In other words, expanding element 20 (which in the case illustrated herein is spherical in shape) is a movable element, preferably a sliding element, susceptible of moving between the extracted condition and the retracted condition.

Retaining element 22 shown herein has a substantially annular shape, and includes a seat 24 formed on the face of retaining element 22 which is closer to pin 10. Said seat is a recess so shaped as to easily receive expanding element 20, which in this case consists of a pair of balls.

In the illustrated example, seat 24 advantageously has a continuous annular development along the entire retaining element 22, so as to be able to receive expanding element 20 irrespective of the angle between pin 10 and retaining element 22.

In accordance with further variant embodiments (not shown), device 1 comprises multiple seats 24 arranged on retaining element 22, each one intended for receiving one or more expanding elements 20.

Retaining element 22 may have different shapes, preferably compliant with the shape of the cross-section of pin 10, such as: square, rectangular, triangular, polygonal, open section, “C” section, etc.

With reference to FIG. 3, device 1 is in the retracted position, in which expanding elements 20 (in this case, balls) are close to axis x-x and do not protrude past the outer surface of pin 10. Balls 20 are not in contact with retaining element 22, and therefore a relative movement (along the axis x-x) is possible between pin 10 and retaining element 22, which allows pin 10 to be extracted from apertures 12, 14 and tooth 3 to be disengaged from tooth adapter 4 of bucket 5.

In the illustrated embodiment, device 1 comprises at least one duct 26, formed in pin 10 and allowing the reversible movement of the at least one expanding element between the extracted condition and the retracted condition.

FIG. 4 shows device 1 in the extracted position, in which balls 20 protrude at least partially past the outer surface of pin 10 for mechanically cooperating with retaining element 22 to prevent any relative movement between pin 10 and retaining element 22, so as to firmly engage tooth 3 with tooth adapter 4 of bucket 5.

Device 1 further comprises an actuator 30 adapted to allow said at least one expanding element 20 to reversibly switch from the retracted position to the extracted position.

In particular, as shown in FIGS. 3 and 4, actuator 30 is a threaded screw to be at least partially inserted into a hole 32 provided on the pin. A user will act upon screw 30, typically by means of a wrench, in order to bring said screw 30 closer to the at least one expanding element until they come in contact with each other; at this point, the tip of screw 30 will push, as it goes forwards, expanding element 20 towards a position farther away from axis x-x, i.e. towards the extracted position, thus securing tooth 3 to bucket 5 and allowing the excavating machine to be normally used. Likewise, when tooth 3 needs to be replaced, the user will undo screw 30 to move the at least one expanding element 20 into the retracted condition, thus allowing removal of pin 10.

In FIG. 5 two ducts 26 are visible, through which the two balls 20 slide in order to switch from the retracted position to the extracted position, and vice versa, under the action of actuator 30. Ducts 26 are arranged radially relative to the axis x-x of pin 10, and are substantially straight.

In this variant, screw 30 is coaxial to pin 10.

However, actuator 30 may also move along an axis that does not coincide with axis x-x.

If actuator 30 is a threaded screw, it is also conceivable to use a self-locking element, or self-locking material, suitable for preventing the screw from loosing accidentally and causing expanding element 20 to move from the extracted position to the retracted position.

According to a further embodiment (not shown), actuator 30 can move said at least one expanding element 20 by means of a gear or a gear system.

According to yet another embodiment, actuator 30 can move said at least one expanding element 20 by means of a lever or a lever system.

For simplicity, retaining element 22 will be referred to below as a “ring”, without however limiting the scope of the invention.

FIGS. 6 and 7 illustrate a second embodiment of the present invention, which comprises an elastic means 34 capable for bringing said at least one expanding element 20 towards one of the extracted position and the retracted position. Advantageously, elastic means 34 is a spring, such as a coil spring. Other per se known elastic means 34 may alternatively be used, such as, for example, a disk spring, or an elastically deformable element, such as a reed or a small bar, a rubber element, or chemical materials having an elastic behaviour.

Preferably, elastic means 34 is adapted to bring expanding element 20 towards the extracted position.

After having inserted pin 10 through holes 12, 14 of tooth 3 and of tooth adapter 4, the user will associate the ring with pin 10; then, by operating actuator 30, the user will bring the expanding element into the extracted condition in order to mechanically secure the ring to pin 10, thereby preventing them from mutually sliding along axis x-x, hence securing tooth 3 to tooth adapter 4. Thanks to the presence of elastic means 34, which will tend to hold expanding elements 20 in the extracted position, in order to place the ring into the correct position along axis x-x of pin 10 the user will have to slide the ring along pin 10 against the resistance opposed by elastic means 34, which will tend to hold expanding elements 20 in the extracted condition. In fact, when pin 10 is not associated with the ring, expanding elements 20 protrude at least partially from the external side surface of pin 10, and therefore the ring will encounter an obstacle while sliding along pin 10.

In the absence of elastic means 34, there is a risk that the ring might be incorrectly secured to pin 10. In fact, in difficult working conditions the user might bring expanding element 20 into the extracted condition without however positioning the ring to correctly receive expanding element 20 (i.e. without the ring and pin 10 being properly aligned along axis x-x). In such a situation, pin 10 might slide off the ring, resulting in the risk that pin 10 might come out of the holes of tooth 3 and of tooth adapter 4, thus causing the tooth to be detached from the tooth adapter.

Therefore, the presence of elastic means 34 prevents the risk that the ring might be incorrectly secured to pin 10, because it will be easy for the user to understand when pin 10 and the ring are in the proper mutual position, and then to operate actuator 30 in order to lock expanding elements 20 in the extracted condition, thus securing tooth to tooth adapter 4. After the ring has been properly positioned on pin 10, expanding elements 20 will, through the effect of elastic means 34, move away from axis x-x of pin 10, arranging themselves in the extracted condition in abutment with seat 24 of the ring; at this stage, a short vibration and a “clack” noise may be generated because of the sudden movement of expanding elements 20. The user can thus easily perceive that pin 10 and the ring have been properly engaged.

In the illustrated example, elastic means 34 is positioned between two expanding elements 20, and exerts a repulsion force on such expanding elements 20 that tends to move them away from axis x-x into the extracted position. A first end (on the right in the drawing) of elastic means 34 is in contact with one expanding element 20, while a second end (on the left) of elastic means 34 is in contact with the other expanding element 20. Elastic means 34 is arranged in ducts 26.

According to another variant (not shown), pin 10 may be equipped with one elastic means 34 for each expanding element 20. Elastic means 34 may be associated with an abutment portion of pin 10; thus, a first end of elastic means 34 is in contact with one expanding element 20, and a second end of elastic means 34 is associated with the abutment portion.

With particular reference to the illustrated embodiment comprehensive of elastic means 34, in the absence of actuator 30 one can engage/disengage pin 10 and the ring by applying a force overcoming the force exerted by elastic means 34 to hold the expanding elements 20 in the extracted condition, thus allowing mutual sliding between pin 10 and the ring. In this case, actuator 30 will contribute to hold expanding means 20 more firmly in said extracted condition in contact with the ring, thus minimizing the risk that pin 10 and ring might accidentally come off.

In the particular variant embodiment shown in Figures and 7, the outer surface of pin 10 has a shape that limits the sliding of the ring along axis x-x of the same pin 10.

Advantageously, the outer surface of pin 10 has two different cross-sections along its axis x-x (the cross-sections are perpendicular to the axis x-x). In particular, pin 10 includes a first portion 10 a with a smaller cross-section and a second portion 10 b with a larger cross-section. In the variant that uses a substantially cylindrical pin 10, the two cross-sections are two circumferences having different diameters.

Portion 10 a of pin 10 that extends from a first end of the latter (the upper end in FIG. 6) to expanding elements 20 has a smaller cross-section; the remaining portion 10 b of pin 10 has a larger cross-section. Thus, the outer surface of pin 10 has a configuration that resembles two superimposed coaxial cylinders.

The difference between the cross-sections of the two portions 10 a, 10 b of the outer surface of pin 10 creates a projection (i.e. an abutment, a stop portion or the like) which is useful for limiting the sliding movement of the ring along pin 10, so that the ring can be correctly positioned on pin 10 during the insertion step. Therefore, after having inserted pin 10 through tooth 3 and tooth adapter 4, the user will push the ring towards pin 10; the ring will slide over pin 10 until it meets the projection, where it will stop. At this point, pin 10 and the ring will be in the correct mutual position that will allow expanding elements 20 to move into the extracted condition within seat 24 of the ring, thereby securing the assembly.

The presence of elastic means 34 and of the projection on the outer surface of pin 10 allows the operator to associate together pin 10 and the ring in a faster, easier and more reliable manner, thereby minimizing the risk of incorrect assembly and obtaining a confirmation that the parts have been assembled correctly.

It must be pointed out that the features of elastic means 34 and of the projection may be individually present in device 1 of the invention, and that they may be combined with any other features of the present invention, unless they are technically incompatible.

As can be seen in some of the drawings, device 1 may be so shaped as to be able to receive a tool or wrench, so that said device 1 can be held while an operator is acting upon actuator 30. For example, if actuator 30 is a screw, on the side opposite to said screw there may be a housing adapted to receive a second tool (e.g. an Allen wrench), so that the necessary torque can be applied without device 1 turning within apertures 12, 14.

Optionally, device 1 comprises a housing formed on pin 10 and shaped for receiving a tool or wrench. Housings are generally formed at the ends of pin 10, along the longitudinal axis x-x thereof. Device 1 illustrated in FIG. 6 comprises a pair of housings: the first housing 40 is located at hole 32 that accommodates actuator 30 (upper part of the drawing), and the second housing 42 is formed at the end of portion 10 b of the pin (lower part of the drawing).

Advantageously, device 1 comprises a closing element 50, 52, e.g. a plug or the like, for closing the respective housing. This will avoid undesired entry of debris and dirt, ensuring better efficiency and a longer life of device 1.

Closing element 50, 52 is removable, thus allowing the tools to be inserted into respective housing 40, 42. Closing element 50, 52 may be made of any material; preferably it is made of rubber or plastic. Closing element 50, 52 may have many different shapes, e.g. cylindrical, truncated cone, parallelepiped, etc.

Of course, without prejudice to the principle of the invention, the forms of embodiment and the implementation details may be extensively varied from those described and illustrated herein by way of non-limiting example, without however departing from the scope of the invention as set out in the appended claims. 

1. A device for securing teeth to a tooth adapter of an earth-moving machine by pins, comprising: a pin removably insertable through at least one first aperture on a tooth and one second aperture on a tooth adapter of said machine; said pin comprising: at least one expanding element adapted to reversibly switch from a retracted position to an expanded position by moving in a plane substantially perpendicular to a longitudinal axis of said pin; said at least one expanding element comprising a sliding element adapted for sliding between said expanded position and said retracted position; at least one duct formed in said pin and providing reversible movement of said at least one expanding element between the expanded position and the retracted position; a screw, at least partially insertable into a hole provided in said pin, adapted to allow said at least one expanding element to reversibly switch from said retracted position to said expanded position; at least one annular ring associable with at least one of said first and second apertures, and provided with at least one seat for at least partially receiving said at least one expanding element when said at least one expanding element is in said expanded position.
 2. The device according to claim 1, wherein said seat has a continuous annular portion along the entire annular ring.
 3. (canceled)
 4. (canceled)
 5. The device according to claim 1, comprising elastic means for bringing said at least one expanding element towards one of said expanded position and said retracted position.
 6. The device according to claim 5, wherein said elastic means are capable of bringing said expanding element towards said expanded position.
 7. The device according to claim 1, wherein an outer surface of said pin has a shape that limits sliding of said annular ring along the longitudinal axis of said pin.
 8. The device according to claim 7, wherein an outer surface of said pin has two different cross-sections along the longitudinal axis.
 9. The device according to claim 8, wherein a part of the pin which extends from a first end of the pin to said at least one expanding element has a smaller cross-section; a remaining part of the pin has a larger cross-section; a difference between the cross-sections of said parts creating a projection which limits sliding of said annular ring along said pin. 10.-14. (canceled)
 15. The device according to claim 1, wherein said at least one expanding element moves in a substantially radial manner relative to the longitudinal axis of said pin.
 16. The device according to claim 1, wherein said at least one expanding element comprises at least one ball.
 17. The device according to claim 1, wherein said at least one expanding element comprises at least one bar.
 18. The device according to claim 1, wherein an outer surface of said pin is substantially cylindrical in shape.
 19. The device according to claim 1, wherein an outer surface of said pin is substantially prismatic in shape.
 20. The device according to claim 1, comprising: a housing formed on said pin and shaped for receiving a tool or wrench; and a closing element for closing the housing.
 21. An assembly comprising: a tooth having at least one first aperture; a tooth adapter having at least one second aperture; a device according to claim 1; wherein said annular ring is at least partially insertable into a cavity formed on at least one of said first aperture and said second aperture; said pin being removably insertable through at least said first aperture and said second aperture. 